The invention relates generally to pressure transducers and specifically to output devices for pressure transducers.
Pressure transducers are used for measuring the pressure of a fluid in a device or system. Pressure transducers may typically provide two types of outputsxe2x80x94(1) a cable connection for transmitting a signal representative of the sensed pressure to a remote monitoring or control device and (2) a human-readable display for providing a local reading of the sensed pressure.
Installation requirements for pressure transducers in the field may impose particular space or configuration requirements on the design of output devices for the pressure transducers. One use of a pressure transducer is to measure the pressure of a gas line. A pressure transducer is typically connected to a gas line such that it is perpendicular to the gas line. The connection between the pressure transducer and the gas line typically includes a passage for the fluid whose pressure is being measured, with a valve to an inlet to a sensing chamber in the transducer. When a pressure transducer is installed on a gas line, it is generally preferable that the passage provided in the connection be positioned so that it is parallel to the direction of flow in the gas line to avoid interruption of the flow. Accordingly, the position of the gas line will dictate the orientation of the pressure transducer. In many applications there are similar constraints on where a pressure transducer may be installed and how it may be positioned.
It is important that the cable connector and/or the display provided for output from a pressure transducer be accessible under various installation conditions. A local display should be oriented so that it is convenient and easy to read. A cable connector should be oriented so that it can easily be connected to the appropriate cable. When a pressure transducer is installed in the field, one or more sides of the pressure transducer may be obscured or obstructed, requiring the outputs to have particular orientations in order to be accessible. Limited vantage points might be available for viewing a display. In addition, under certain circumstances, a display having a particular orientation or a cable connector facing in a particular orientation may be especially desirable. It may be important for a number of displays to be aligned, for example, to form a xe2x80x9cbankxe2x80x9d of displays by positioning several transducers and their associated displays together on a set of gas lines. Given these requirements, pressure transducers having different configurations of cable connectors and local displays, particularly relative to the fluid passage of the pressure transducer, are generally needed for different applications. To satisfy this need, manufacturers have typically provided each type of transducer in several different configurations, each configuration having a unique placement, or orientation, of the display. However, carrying inventory for multiple configurations of the same transducer is expensive.
A measuring indicator device for a pressure transducer is disclosed in U.S. Pat. No. 6,119,524, entitled xe2x80x9cMeasuring Indicator Device,xe2x80x9d issued Sep. 19, 2000, to Kobold. The display disclosed in the ""524 patent is screwed onto a casing. A pressure transducer and a line socket are connected on opposite sides of the casing. The casing is rotatable around its longitudinal axis. The position of the display can be adjusted by rotating the casing. Although the position of the display disclosed in the ""524 patent may be adjusted, the disclosed design does not eliminate the need for providing multiple configurations of the same transducer. For example, FIGS. 1 and 2 of the ""524 patent show two such configurations in which the display has been screwed into the casing at two different orientations which are rotated ninety degrees from one another.
An adaptable, easily adjustable output device for pressure transducers is needed.
The present invention is directed to an adjustable output device for pressure transducers and a method for installing and adjusting the output device. An output device constructed in accordance with the present invention may be field-configured in a multitude of ways, largely eliminating the need for preselecting particular output devices for particular installations. An output device constructed in accordance with the invention incorporates a cable connector and an electronic display. In one aspect of the invention, both the cable connector and the electronic display can be selectably positioned relative to the pressure transducer.
In one aspect of the invention, the orientation of the electronic display relative to the cable connector is adjustable. The electronic display is adjustable such that the digits of the display can generally be viewed right-side up or in the orientation most convenient to the user, given the constraints of a particular installation. The electronic display is rotatable around an axis perpendicular to the plane of the display. In some embodiments of the invention, the output device is substantially cylindrical in form. One end of the output device connects to a pressure transducer. The electronic display is disposed on the opposite end of the output device. In some embodiments, the display is disposed transverse to the longitudinal axis of the output device so that it can be seen from above, e.g., by forming an endcap for a generally cylindrical output device. The display can be rotated around the longitudinal axis of the output device in some embodiments. The orientation of the display can be adjusted without the use of tools and without taking apart the device or removing mechanical fasteners such as screws.
In another aspect of the invention, the orientation of the cable connector relative to the pressure transducer is adjustable. In one aspect of the invention, the output device may connect to the pressure transducer in a number of orientations. The orientation of the output device relative to the pressure transducer selects the orientation of the cable connector. In some embodiments, the cable connector is positioned on the side of the output device. The position of the output device may be changed without the use of tools. In some embodiments, the adjustability of the output device is provided through a bayonet connection between the output device and the pressure transducer.
These and other features and advantages of the present invention will become readily apparent from the following detailed description, wherein embodiments of the invention are shown and described by way of illustration of the best mode of the invention. As will be realized, the invention is capable of other and different embodiments and its several details may be capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not in a restrictive or limiting sense, with the scope of the application being indicated in the claims.